ACS712.h

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#pragma once
//
//    FILE: _ACS712.h
//  AUTHOR: Rob Tillaart
// VERSION: 0.2.2
//    DATE: 2020-08-02
// PURPOSE: _ACS712 library - current measurement
//
// Tested with a RobotDyn _ACS712 20A breakout + UNO.
//
 
#include "Arduino.h"
 
#define ACS712_LIB_VERSION (F("0.2.2"))
 
//  ACS712_FF_SINUS == 1.0/sqrt(2) == 0.5 * sqrt(2)
//  should be smaller in practice 0.5 ?
#define ACS712_FF_SINUS    (1.0 / sqrt(2))
#define ACS712_FF_SQUARE   (1.0)
#define ACS712_FF_TRIANGLE (1.0 / sqrt(3))
 
 
class _ACS712
{
  public:
    //  NOTE:
    //  One can quite precisely tune the value of the sensor
    //      (1) the milliVolt per Ampere and
    //      (2) the volts parameter.
    //
    //  TYPE  mV per Ampere
    //  5A    185
    //  20A   100
    //  30A   66
    _ACS712(uint8_t analogPin, float volts = 5.0, uint16_t maxADC = 1023, uint8_t mVperA = 100);
 
 
    // returns mA
    // blocks 20-21 ms to sample a whole 50 or 60 Hz period.
    // lower frequencies block longer.
    int mA_AC(uint8_t freq = 50);
 
 
    // returns mA
    // blocks < 1 ms
    int mA_DC();
 
 
    // midpoint ADC for DC only
    inline void setMidPoint(uint16_t mp)
    {
        _midPoint = mp;
    };
    inline uint16_t getMidPoint()
    {
        return _midPoint;
    };
    inline void incMidPoint()
    {
        _midPoint++;
    };
    inline void decMidPoint()
    {
        _midPoint--;
    };
    // Auto midPoint, assuming zero DC current or any AC current
    void autoMidPoint(uint8_t freq = 50);
 
 
    // also known as crest factor;  affects mA_AC() only
    // default sinus.
    inline void setFormFactor(float ff = ACS712_FF_SINUS)
    {
        _formFactor = ff;
    };
    inline float getFormFactor()
    {
        return _formFactor;
    };
 
 
    //  noise defaults 21
    inline void setNoisemV(uint8_t noisemV = 21)
    {
        _noisemV = noisemV;
    };
    inline uint8_t getNoisemV()
    {
        return _noisemV;
    };
 
 
    // AC and DC
    inline void setmVperAmp(uint8_t mva)
    {
        _mVperAmpere = mva;
    };
    inline uint8_t getmVperAmp()
    {
        return _mVperAmpere;
    };
 
 
  private:
    uint8_t _pin;
    float _mVpstep;    // millivolt per step
    float _formFactor; // point2point -> RMS
    uint8_t _mVperAmpere;
    uint16_t _midPoint;
    uint8_t _noisemV;
};
 
// -- END OF FILE --